Concave cover plate system and methods

ABSTRACT

The present invention comprises a removable cover plate assembly, which may be quickly attached, detached and adjusted to the exterior of a concave grate of a combine harvester in order to adjust the flow characteristics of the concave or separator grate assemblies. The cover plate assembly improves the threshing capability of the rasp bar threshing cylinder while simultaneously capturing additional threshed grain. Moreover, the cover plate assembly of the present invention enables a single set of concave grate assemblies to better harvest a wider variety of crop types.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 16/050,714 filed Jul. 31, 2018, which is acontinuation application of U.S. patent application Ser. No. 15/832,142filed Dec. 5, 2017, the technical disclosure of which is herebyincorporated herein by reference.

BACKGROUND OF THE INVENTION Technical Field of the Invention

This invention relates to agricultural harvesting machines of the typethat use rotary processing devices, and particularly to a threshingmechanism in which a rotary threshing cylinder cooperates with concavethreshing and separator grates with openings, and more particularly witha means for at least partially closing the concave grates by theattachment of one or more cover plates to provide maximum harvestingversatility.

Description of the Related Art

An agricultural harvester, most commonly known as a combine harvester,is a vehicle used for the harvesting of agricultural crops. Prior artcombine harvesters are typically composed of several systems to pick,thresh, separate, clean and retain the grain from the particular cropbeing harvested. For example, in one type of prior art combineharvester's threshing system, the crop travels axially parallel to andhelically around the rotational axis of one or more rotary processingdevices commonly referred to as rotors. In other prior art combineharvester's threshing systems, during at least a portion of its travelthrough the system, the crop travels in a transverse or tangentialdirection relative to the rotational axis of a rotary processing devicecommonly referred to as a threshing cylinder. In each of the prior artthreshing systems, crop material is processed between rasp elementsattached to the periphery of a rotary device and arcuate grates, usuallyforaminous, stationary threshing concaves and separating grates that atleast partially wrap around the rotor. The typical threshing concaveused with a rasp bar threshing cylinder consists essentially of anarcuate grate, roughly concentric with the threshing cylinder. The cropmaterial travels around the rotary cylinder and is “wedged” in betweenthe rotary cylinder and threshing concaves causing the grain to beremoved from the stalk.

For example, Regier (U.S. Pat. No. 9,215,845) discloses an exemplaryprior art combine harvester. As shown in FIG. 1, the depicted combineharvester 10 has a single axial flow rotary processing system 12 thatextends generally parallel with the path of travel of the machine.However, as will be seen, the principles of the present invention arenot limited to combine harvesters having only a single axial flow rotaryprocessing system. For the sake of simplicity in explaining theprinciples of the present invention, this specification will proceedutilizing a combine harvester having a single axial flow processingsystem as the primary example.

The exemplary prior art combine harvester 10 depicted in the illustratedembodiment includes a harvesting header (not shown) at the front of themachine that picks or cuts the harvested crop and delivers the collectedcrop material to the front end of a feeder house 14. A conveyor 16 movesthe crop material rearwardly within the feeder house 14 until reachingthe processing system 12. With reference now to FIG. 2, the illustratedembodiment the exemplary prior art processing system 12 has a rotor 20having an infeed auger 22 on the front end thereof. The auger 22 androtor 20 advance the crop material axially through the processing system12 for threshing and separating. The rotor 20 typically includes aplurality of rasp-like elements 55, configured about the rotor'speripheral surface. The rotor is partially encased by a series ofthreshing concave grate assemblies 24 and separator grate assemblies 26.As the crop material moves around and in-between the rasp-like elements55 and the threshing concave grate assemblies 24, the crop is threshed.Any free grain, that has been threshed, falls through openings in theconcave grate assemblies 24, 26 and is retained by the combineharvester. In other types of processing systems, a conveyor 16 maydeliver the crop material directly to a threshing cylinder.

Generally speaking, the crop material entering the processing system 12moves axially and helically through the system during threshing andseparating. During such travel the crop material is threshed andseparated by rotor 20 operating in cooperation with preferably concaveforaminous separator 23 in comprising at least one threshing concavegrate assembly 24 and a concave separator grate assembly 26, with thegrain escaping laterally through threshing concave grate assemblies 24and concave separator grate assemblies 26 into a cleaning mechanism 28(FIG. 1). Bulkier stalk and leaf material is retained by the threshingconcave grate assemblies 24 and separator grate assemblies 26 andejected out of the processing system 12 at the rear of the combineharvester 10. The cleaning mechanism 28 may further include a blower(not shown), which provides a stream of air directed throughout thecleaning region below processing system 12 and out the rear of theharvester 10 so as to carry lighter chaff particles away from the grainas it migrates downwardly toward the bottom of the machine to a cleangrain auger 30. The auger 30 delivers the clean grain to an elevator(not shown) that transfers the grain to a storage bin 34 on top of themachine, from which it is ultimately unloaded via an unloading spout 36.

A plurality of threshing concave grate assemblies 24 and concaveseparator grate assemblies 26 are arranged side-by-side axially alongthe processing system 12 to form a part of what may be considered atubular housing 38 that concentrically receives rotor 20 and serves aspart of processing system 12. In the illustrated embodiment, threethreshing concave grate assemblies 24 and three concave separator gratesassemblies 26 form part of the tubular housing 38. However, it isunderstood that more or fewer threshing concave grate assemblies 24 andconcave separator grate assemblies 26 may be used in the tubular housing38. As is known in the art, the tubular housing 38 includes a convex topwall (not shown) that extends the full length of housing 38 andeffectively closes off the top portion thereof from front to rear. Thethreshing concave grate assemblies 24 and concave separator grateassemblies 26 are moved adjustably toward and away from rotor 20 toadjust the running clearance between the rotor 20 and concave andseparator grate assemblies 24, 26 and to change the shape of thethreshing and separating regions as is known in the art and need to befurther discussed herein.

As best seen in FIG. 3A, each threshing concave grate assembly 24typically includes an arcuate first grate 40 and an arcuate second grate42 pivotally mounted in the processing system 12. A suitable actuator(not shown) is located near the processing system 12 and mounted onportions of the combine harvester frame structure. Preferably, theactuator is remotely operable, such as from the cab of harvester 10.Grates 40 and 42 of each threshing concave grate assembly 24 desirablyhave substantially similar structure but mirror images, so only grate 40will be described in detail herein. Additionally, the invention isdescribed herein with respect to a grate of the threshing concave grateassembly 24, but one skilled in the art will understand that theinvention may also be used with a concave separator grate assembly 26without departing from the scope of the invention.

As shown in FIG. 3B, a conventional prior art threshing concave grate 40typically includes a pair of arcuate, elongated and laterally spacedapart side rails 44 oriented generally transverse to the axis of therotor 20. One end of each side rail 44 has a hook element 46 used tomount the threshing concave grate assembly 24 on an axial bar (notshown) used to move the threshing concave grate 24 toward or away fromthe rotor 20 (FIG. 2). A plurality of axial bars 48 spaced atpredetermined intervals span the side rails 44. End plates 49 arepreferably affixed between ends of the side rails 44. The axial bars 48typically have outwardly projecting overhangs 50 at their opposite endsthat overlay upper edges of the side rails 44 and are operable to bearagainst the same when grate 40 is installed. Preferably, the overhangs50 are received in notches 52 in the upper edges of side rails 44 andwelded to the side rails 44. Overhangs 50 also provide a substantiallycontinuous surface when multiple grate assemblies 26 are installedside-by-side in the harvester 10. One or more middle supports 51 aretypically positioned between and parallel to the side rails 44 andsupport the axial bars 48.

Each threshing concave grate 40 is customized for a particular crop typeby varying the size, number, shape and spacing of the axial bars 48. Thevarious threshing concave grates 40 are typically swapped out dependingupon the crop being harvested. While the plurality of axial bars 48shown in the figures are depicted as having a generally roundcross-section with a partially flattened top or interior surface, it isunderstood that the axial bars cross section may alternatively becompletely round, notched, oval, square or polygonal.

Conventional combine harvesters are utilized to harvest a wide varietyof different crops. Farmers generally harvest several crops each yearand crop rotation is a standard agricultural practice. However, somecrops are easier to thresh (i.e., separate grain or seed from chaff)than others. The threshing concave grates are typically customized forthe type of crop being harvested. For example, sunflower seeds can beharvested with a simple shake of the stem of the plant, whereas somevarieties of wheat must be vigorously rubbed together for many secondsfor the seeds to separate from the chaff. For some crops and operations,it is desirable for the lateral spacing between adjacent axial bars 48of a threshing concave grate 40 to be very narrow in order to modify thethreshing and separating action. The threshing concave grates 40 forharder to thresh grains typically have axial rods 48 that are spacedclose together and restrict airflow through the concave so that thematerial remains in the threshing section longer and hence is more fullythreshed by the time it gets to the separation concave grating whosepurpose is to capture the threshed grain. However, threshing concavegrates 40 are heavy and their installation is time consuming and costlyduring harvest season. Thus, it is oftentimes desirable to adjust theflow of crop material over the threshing concave grates and separatorgrates to give the rotor more opportunity to thresh and separate thecrop material.

While the basic design of the conventional rasp bar cylinder andthreshing concave is long practiced, numerous patents directed at meansfor modifying the characteristics of the threshing concave grates,including devices and methods for closing or partially closing openingsin the concave grate, continue to appear. However, prior art solutionsto closing or partially closing threshing concave grates have oftentimesbeen cumbersome in application and inefficient in flexibility of use.For example, Lindgren (U.S. Pat. No. 2,159,664) discloses using multipleinsert filler plates configured between adjacent grate bars to adjustthe flow characteristics of a threshing machine. However, the Lindgreninvention requires the modification of side bars of the concave (addingpins to help retain the filler strip) and relies on a fastening meanswhich requires access from both the inner and outer sides of theconcave. However, swapping out or even adjusting threshing concavegrates in the field is a laborious task and often requires two or threepeople several hours to remove or adjust because of their size, weightand tight compartment constraints.

Young (U.S. Pat. No. 2,686,523), Morgan (U.S. Pat. No. 3,092,115),Baumeister et al. (U.S. Pat. No. 3,191,607) and Davidow et al (U.S. Pat.No. 3,439,684) all disclose systems of multiple filler strips attachedto the inside of the threshing concave grates between the axial barstraversing the side rails. Although these systems are effective, theyare cumbersome to attach and adjust to a threshing concave grate, andsusceptible, in some operating conditions, to becoming detachedresulting in the filler strip or components thereof being sucked intothe downstream material flow, possibly with some damage to combinecomponents. Furthermore, yet again, one must remove the concave grateassembly to access the inner portion of the threshing concave grate toattach the filler plate, which is simply not practical, especiallyduring time-sensitive harvest season.

Yarbrough (U.S. Pat. No. 4,495,954) discloses a system of filler stripassembly attached to the inside of the threshing concave grate withmechanical screw fasteners. However, the filler strip assembly covers upthe threshing elements of the threshing concave grate eliminating anythreshing action by threshing concave grate. Moreover, the disclosedfiller strips are solid and without openings so none of the resultinggrain can readily escape and be captured.

A need, therefore, exists for an improved and more comprehensivemechanism for readily closing or partially closing the opening in aconcave or separator grate assembly so as to modify its threshing andseparating action. Moreover, a need exists for an improved and morecomprehensive mechanism for closing or partially closing the opening ina concave or separator grate assembly that may be readily installed andadjusted in the field.

SUMMARY OF THE INVENTION

The present invention overcomes many of the disadvantages of changingthe flow characteristics of prior art combine harvester's concave andseparator grate assemblies by providing a removable cover plateassembly, which may be quickly attached, detached and adjusted to theexterior of a threshing concave grate in order to adjust the flowcharacteristics of the concave or separator grate assemblies. While theinvention is described herein with respect to a grate of the threshingconcave grate assembly, one skilled in the art will understand that theinvention may also be used for the separator grate assembly withoutdeparting from the scope of the invention.

The cover plate assembly of the present invention improves the threshingcapability of the rasp bar threshing cylinder while simultaneouslycapturing additional threshed grain. Moreover, the cover plate assemblyof the present invention enables a single set of threshing concave grateassemblies to better harvest a wider variety of crop types.

The cover plate assembly comprises an elongated plate body dimensionedto be positioned between two parallel arcuate rails of a threshingconcave grate assembly. For example, a preferred embodiment of the coverplate assembly of present invention includes an elongated plate bodydimensioned to be positioned between an arcuate side rail and middlesupport rail of a threshing concave grate assembly. The cover plateassembly is designed to be configured in a curved supinated positionagainst the plurality of axial bars or rods on the exterior of thethreshing concave grate assembly. The opposing ends of the cover plateassembly are secured to the axial bars or rods by means of hooking claspelements formed in the opposing ends of the cover plate. The hookingclasp elements have a dimensional shape that is complementary to thecross-sectional shape of the axial bars or rods, such that they can beeasily and quickly attached and slidably locked in place by a simple tugalong the longitudinal axis of the cover plate.

The cover plate assembly further includes a latching mechanism thatmaintains the lateral position of the cover plate so that the hookingclasp elements stay locked about their respective axial bars. Forexample, in a preferred embodiment the latching mechanism comprises aturn-buckle tension device configured between an anchor device securedto an end plate of the threshing concave grate assembly and an anchorbracket attached to the exterior-facing side of the cover plate. Inanother embodiment, the latching mechanism comprises a tension drawlatch assembly. Indeed, one skilled in the art will understand that awide variety of latching mechanisms can be employed to apply a tensionforce between the anchor bracket attached to the cover plate elongatedbody and the anchor device secured to an end plate of the threshingconcave grate assembly.

In another preferred embodiment, the latching mechanism may comprise aturn-buckle tension device configured between an anchor device securedto a side rail of the concave grate assembly and an anchor bracketattached to the exterior-facing side of the cover plate. Alternatively,the anchor device may be secured to a bar extending between the opposingside rails of the concave grate assembly. The anchor bracket may rigidlyattached (e.g., welded) or pivotally attached (e.g., by means of apivoting rivet assembly) to the exterior-facing side of the cover plate.

In yet another alternative embodiment, the cover plate of the presentinvention may include one or more side latching mechanisms that maintainthe lateral position of the cover plate within the side rails so thatthe hooking clasp elements stay locked about their respective axialbars. The side latching mechanisms may be used as an alternative to orin addition to the previously disclosed end latching devices. Forexample, in a preferred embodiment the side latching mechanism maycomprise a sliding bolt latch mechanism attached to the cover plate andconfigured to engage a hole drilled in the side rail of the concavegrate assembly. In another embodiment, the side latching mechanism maycomprise a tension draw latch assembly configured to engage a latchcatch attached to or formed into the side rail of the concave grateassembly. Indeed, one skilled in the art will understand that a widevariety of side latching mechanisms can be employed to secure theconfiguration of the cover plate on the concave grate assembly.

The cover plate may also include one or more accessory brackets attachedto the exterior-facing side of the cover plate to assist the user inproperly positioning and initially securing of the cover plate to athreshing concave grate assembly.

When properly installed, the elongated body of the cover plate assemblyis pulled tightly against the back of the exterior side of the threshingconcave grate assembly significantly changing airflow characteristicsthrough the concave openings and consequently creating a cushion of airbetween concave and the cylinder of the combine. This cushion of airregulates the rate at which the crop material moves through the concavesection. By restricting the airflow through a threshing concave grateassembly the time in which the crop is in the threshing section of theconcave is prolonged which facilitates more material-on-material rubbingcontact, thereby greatly improving threshing and separation of grainfrom chaff for hard-to-thresh crop types and varieties.

The elongated body of the cover plate assembly is preferably constructedof a single plate of high strength material such as metal, high strengthplastics or composite fabric material. While a preferred embodiment ofthe cover plate assembly is constructed of steel plating that ispermanently bent in an arcuate shape matching the exterior arcuate shapeof a threshing concave grate assembly, it is understood that theelongated body of the cover plate assembly may be constructed offlexible, high strength materials such as stainless steel or wovencomposite materials. Alternatively, the elongated body can also be castinto a predetermined arcuate shape. In addition, while a preferredembodiment of the cover plate assembly features an elongated body havinga unitary construction, wherein the hooking clasp elements on opposingends of the assembly are simply formed into the ends of the elongatedbody, it is understood that the elongated body, and the two hookingclasp elements may comprise individual parts of a composite constructionwherein the elongated body and the two hooking clasp elements areconstructed of different materials. For example, the elongated body maybe constructed of a woven plastic material, while the hooking claspelements may be constructed of metal that are attached to the elongatedbody.

Moreover, the material used to construct the elongated body of the coverplate assembly may also have a wide variance of porosity andpermeability. This may be accomplished by a variety of techniques. Whilea preferred embodiment of the cover plate assembly is constructed ofsolid plate material, other embodiments include a plurality of aperturesor holes formed in the elongated body. The holes may be randomly placedor formed in a geometric pattern. The holes increase the airflow throughthe threshing concave grate assembly and provides an exit route forthreshed grain from to be unloaded and captured so that the separationgrate is not overloaded. In addition, the plurality of apertures orholes may further include means for adjusting the shape or size of theaperture.

For example, in one embodiment, such adjusting means may simply comprisea plug device for plugging the aperture. Alternatively, the adjustingmeans may comprise a sliding panel mechanism incorporated into theelongated body that features movable panel sections which could bepositioned to close or partially close a hole or aperture.

The material that the elongated body is constructed of may also have anatural porosity and permeability. For example, the elongated body ofthe cover plate may be constructed of a metal mesh or composite materialhaving organic porosity and permeability characteristics.

The longitudinal length of the elongated body of the cover plateassembly may also be varied to change the characteristics of thethreshing concave grate. While a preferred embodiment of the inventionis suitably dimensioned to substantially cover the entire lateralcircumference of a threshing concave grate assembly, other embodimentsmay include elongated bodies having lesser longitudinal lengths so as tocover only a portion of the lateral circumference of a threshing concavegrate assembly.

Finally, a preferred embodiment of the cover plate assembly of thepresent invention includes an elongated body having an adjustable width.The elongated body is comprised of two elongated plates attached in aslidably adjustable configuration for adjusting the lateral dimension orwidth of the cover plate assembly. In one embodiment, the two elongatedplates are attached by means of a plurality of bolts attached to oneplate and captured in slots formed in a second plate.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the method and apparatus of the presentinvention may be had by reference to the following detailed descriptionwhen taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic side elevational view of a prior art combineharvester having a processing system utilizing axial flow, portions ofthe harvester being broken away to reveal internal details ofconstruction;

FIG. 2 is an enlarged isometric view of the prior art processing systemwithin the prior art harvester of FIG. 1;

FIG. 3A is an enlarged isometric view of a portion of the prior artprocessing system of FIG. 2 showing threshing concave grate assemblies;

FIG. 3B is a partially cut away view of one of the threshing concavegrate assemblies of FIG. 3A;

FIG. 4A is an isometric view of a multiple threshing concave gratesincorporating embodiments of the cover plate assembly of the presentinvention;

FIG. 4B is an isometric view of a multiple threshing concave gratesincorporating alternative embodiments of the cover plate assembly of thepresent invention;

FIG. 5A is a partially cut away view of a threshing concave grateincorporating principles of the cover plate assembly of the presentinvention;

FIG. 5B is an exploded view of the cover plate assembly of the presentinvention shown in FIG. 5A:

FIG. 5C is a partially cut away view of a threshing concave grateincorporating principles of an alternative embodiment of the cover plateassembly of the present invention;

FIG. 5D is an exploded view of the alternative embodiment of the coverplate assembly of the present invention shown in FIG. 5C;

FIG. 6A is a top plan view of the interior side of the cover plateassembly of the present invention shown in FIG. 5A;

FIG. 6B is a top plan view of the exterior side of the cover plateassembly of the present invention shown in FIG. 5A;

FIG. 6C is a top plan view of the interior side of the alternativeembodiment of the cover plate assembly of the present invention shown inFIG. 5C;

FIG. 6D is a top plan view of the exterior side of the alternativeembodiment of the cover plate assembly of the present invention shown inFIG. 5C;

FIG. 7A is an enlarged isometric view of an embodiment of the first orfront end of the cover plate assembly of the present invention;

FIG. 7B is an enlarged isometric view of an embodiment of the second orback end of the cover plate assembly of the present invention;

FIG. 8A is a threshing concave grate incorporating an alternativeembodiment of the cover plate assembly of the present invention; and

FIG. 8B is a threshing concave grate incorporating another alternativeembodiment of the cover plate assembly of the present invention.

Where used in the various figures of the drawing, the same numeralsdesignate the same or similar parts. Furthermore, when the terms “top,”“bottom,” “first,” “second,” “upper,” “lower,” “height,” “width,”“length,” “end,” “side,” “horizontal,” “vertical,” and similar terms areused herein, it should be understood that these terms have referenceonly to the structure shown in the drawing and are utilized only tofacilitate describing the invention.

All figures are drawn for ease of explanation of the basic teachings ofthe present invention only; the extensions of the figures with respectto number, position, relationship, and dimensions of the parts to formthe preferred embodiment will be explained or will be within the skillof the art after the following teachings of the present invention havebeen read and understood. Further, the exact dimensions and dimensionalproportions to conform to specific force, weight, strength, and similarrequirements will likewise be within the skill of the art after thefollowing teachings of the present invention have been read andunderstood.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the Figures, and in particular FIGS. 4A and 4B, multipleembodiments of the cover plate assembly of the present invention areshown attached to conventional threshing concave grates 140. While theinvention is described herein with respect to a grate of the threshingconcave grate assembly, one skilled in the art will understand that theinvention may also be used for the separator grate assembly withoutdeparting from the scope of the invention.

Each of the depicted conventional threshing concave grates 140 include apair of arcuate, elongated and laterally spaced apart side rails 144oriented generally transverse to the axis of the rotor 20 (FIG. 2). Oneend of each side rail 144 has a hook element 146 used to mount thethreshing concave grate 140 on an axial bar (not shown) used to move thethreshing concave grate 140 toward or away from the rotor 20 (FIG. 2). Aplurality of axial bars 148 span the side rails 144. End plates 149 arepreferably affixed between ends of the side rails 144. A middle supportrail 151 is typically positioned between and parallel to the side rails144 and supports the axial bars 148.

The axial bars 148 typically have outwardly projecting overhangs attheir opposite ends that overlay upper edges of the side rails 144 andare operable to bear against the same when grate 140 is installed.Preferably, the overhangs are received in notches 152 (FIG. 5B) in theupper edges of side rails 144 and welded to the side rails 144. Theoverhangs also provide a substantially continuous surface when multiplegrate assemblies 24, 26 (FIG. 1) are installed side-by-side in theharvester 10 (FIG. 1). While the axial bars 148 shown in FIGS. 4A and Bare depicted as having a round or partially round cross section, it isunderstood that the axial bars 148 can also have a completely round,notched, oval, rectangular or polygonal cross-section.

A first embodiment of the cover plate assembly 100 is depicted in FIG.4A. The cover plate assembly 100 comprises an elongated plate body 102dimensioned to be positioned between two parallel arcuate rails (e.g.,arcuate side rail 144 and middle support rail 151) of a threshingconcave grate 140. The cover plate assembly 100 is designed to beconfigured in a curved supinated position against the plurality of axialbars 148 on the exterior of the threshing concave grate 140.

The opposing ends of the elongated plate body 102 of the cover plateassembly 100 are secured to the axial bars by means of clasp elements104, 106 formed in the opposing ends of the cover plate assembly 100.The clasp elements 104, 106 have a dimensional shape that iscomplementary to the cross-sectional shape of the axial bars 148, suchthat they can be easily and quickly attached from the exterior side ofthe threshing concave grate 140 and slidably locked in place by a simpletug along the longitudinal axis of the cover plate assembly 100. Bothclasp elements 104, 106 extend from or are configured on the interiorfacing surface 102 a of the elongated body 102.

For example, as shown in FIGS. 5B and 7A, the cover plate assembly 100includes a U-shaped clasp element 104 formed in the first or front endof the elongated plate body 102. The complementary shape of the U-shapedclasp element 104 enables it to be inserted from the exterior side ofthe threshing concave grate 140 and firmly hook on and grasp theinterior or top surface of an axial bar 148 a when the cover plateassembly 100 is moved or rotated towards an anchor device (i.e., to theleft, as depicted in FIG. 5B) installed on the interior surface of theend plate 149 of the threshing concave grate 140.

Similarly, as shown in FIGS. 5B and 7B, the cover plate assembly 100further includes an inverted L-shaped clasp element 106 formed in thesecond or back end of the elongated plate body 102. The shape of theinverted L-shaped clasp element 106 enables it to also be inserted fromthe exterior side of the threshing concave grate 140 so that a ledge orsurface 107 engages the top surface of another axial bar 148 a′ when thecover plate assembly 100 assembly is moved or rotated towards an anchordevice (i.e., to the left, as depicted in FIG. 5B) installed on theinterior surface of the end plate 149 of the threshing concave grate140.

Preferably, the cover plate assembly 100 is configured so that the claspelements 104, 106 simultaneously engage their respective axial bars 148when the cover plate assembly 100 is rotated or moved into its firstembodiment of the cover plate assembly 100 is depicted locked position.The cover plate assembly 100 may also include one or more accessorybrackets 112 attached to the exterior-facing side 102 b of the coverplate body 102 to assist the user in properly positioning and initiallysecuring of the cover plate assembly 100 to a threshing concave grate140.

The cover plate assembly 100 further includes a latching mechanism 115that maintains the lateral position of the cover plate assembly 100 sothat the clasp elements 104, 106 stay locked in position about theirrespective axial bars 148. For example, as depicted in FIGS. 4A and 5A,in a preferred embodiment the latching mechanism 115 comprises aturn-buckle tension device configured between an anchor device 132secured to an end plate 149 of the threshing concave grate 140 and ananchor bracket 110 attached to the exterior-facing side 101 b of thecover plate body 102. In an alternative embodiment, the latchingmechanism 115 comprises a conventional tension draw latch assembly.Indeed, one skilled in the art will understand that a wide variety oflatching mechanisms can be employed to apply a tension force between theanchor bracket 110 attached to the elongated body 102 and the anchordevice 132 secured to an end plate 149 of the threshing concave grate144.

With reference now to FIGS. 4B, 5C-D and 6C-D, in another preferredembodiment, the latching mechanism 115 may comprise a turn-buckletension device configured between an anchor device 132A secured to aside rail 144 of the concave grate assembly 140 and an anchor bracket110 attached to the exterior-facing side 101 b of the cover plate body102. As shown in FIG. 4B, the anchor device 132B may alternativelycomprise a bar attached to and extending between the opposing side rails144 of the concave grate assembly 140. The anchor bracket 110 may berigidly attached (e.g., welded) to the exterior-facing side 101 b of thecover plate body 102. Alternatively, the anchor bracket 110 maypivotally attached to the exterior-facing side 101 b of the cover platebody 102 by means of a pivoting rivet assembly 111. The pivoting rivetassembly 111 enables an anchor bracket 110 to be properly angled andconfigured for either an end mounted anchor device 132 or a side-railmounted anchor device 132B.

With reference again to FIGS. 4B, 5C-D and 6C-D, in yet anotheralternative embodiment, the cover plate 100 of the present invention mayinclude one or more side latching mechanisms 60 that maintain thelateral position of the cover plate 100 within the side rails 144 sothat the hooking clasp elements 104, 106 stay engaged about theirrespective axial bars 148. The side latching mechanisms 60 may be usedas an alternative to, or in addition to, the previously disclosed endlatching devices (e.g., 110, 115, 132). For example, as shown in FIG. 4Bin a preferred embodiment, the side latching mechanism 60 may compriseat least one sliding bolt latch mechanism 62 attached to the cover plate100 and configured to engage a corresponding hole 63 drilled in the siderail 144 of the concave grate assembly 140. As depicted, the slidingbolt latch mechanism may include a biasing element (e.g., spring or cam)to bias the sliding bolt in the locked or engaged position. In anotherembodiment, the side latching mechanism 60 may comprise at least onetension draw latch assembly 66 configured to engage a latch catch 67attached to or formed into the side rail 144 of the concave grateassembly 140. Indeed, one skilled in the art will understand that a widevariety of side latching mechanisms can be employed to secure theconfiguration of the cover plate body 102 on the concave grate assembly140.

When properly installed and secured in a locked position, the elongatedbody 102 of the cover plate assembly 100 is pulled tightly against theback of the exterior side of the threshing concave grate 140significantly changing airflow characteristics through the openings inthe threshing concave grate 140 and consequently creating a cushion ofair between threshing concave grate 140 and the rotor/cylinder of thecombine harvester. This cushion of air regulates the rate at which thecrop material moves through the concave section. By restricting theairflow through a threshing concave grate, the time in which the crop isin the threshing section of the concave is prolonged, which facilitatesmore material-on-material rubbing contact, thereby greatly improvingthreshing and separation of grain from chaff for hard-to-thresh croptypes and varieties.

The embodiment of the cover plate assembly 100 shown in the Figures ispreferably constructed of a single plate of high strength material suchas metal, high strength plastics or composite fabric material. While apreferred embodiment of the cover plate assembly 100 is constructed ofsteel plating that is permanently bent in an arcuate shape matching theexterior arcuate shape of a threshing concave grate 140 as shown inFIGS. 5B and 5D, it is understood that the elongated body of the coverplate assembly may be constructed of flexible, high strength materialssuch as stainless steel or woven composite materials. Alternatively, theelongated body can also be cast into a predetermined arcuate shapematching the exterior arcuate shape of a threshing concave grate 140. Inaddition, while a preferred embodiment of the cover plate assemblyfeatures an elongated body 102 having a unitary construction, whereinthe clasp elements 104, 106 on opposing ends of the assembly 100 aresimply formed into the ends of the elongated body 102, it is understoodthat the elongated body 102, and the two clasp elements 104, 106 maycomprise individual parts of a composite construction wherein theelongated body and the clasp elements are constructed of differentmaterials. For example, the elongated body 102 may be constructed of awoven, high-strength, plastic material, while the clasp elements 104,106 may be constructed of metal that are attached to opposing ends ofthe elongated body.

Additionally, the material used to construct the elongated body of thecover plate assembly may also have a wide variance of porosity andpermeability. This may be accomplished by a variety of techniques. Whilea preferred embodiment of the cover plate assembly is constructed ofsolid plate material, other embodiments include a plurality of aperturesor holes formed in the elongated body. For example, as shown in FIGS. 4and 6, a second embodiment of the cover plate assembly 100A furtherincludes a plurality of apertures or holes 116 formed in the rectangularbody 102 of the cover plate assembly 100A. The holes 116 may beconfigured randomly or in a geometric pattern as shown in FIGS. 6A-D. Inaddition to increasing the airflow through the cover plate assembly100A, the holes 116 provide additional exit passages for threshed grainto be unloaded from the rotor/cylinder and captured so that theseparation grate is not overloaded. The plurality of apertures or holes116 may further include means for adjusting the shape or size of theaperture 116. For example, in one embodiment, such adjusting means maysimply comprise a plug device 118 for plugging the aperture. The plugdevice 118 can comprise a screw-in or pop-in plug 118 a or aflapper-like cover 118 b. Alternatively, the adjusting means maycomprise a sliding panel mechanism incorporated into the elongated body102 that features a movable panel section 120 which could be configuredto close or partially close a hole or aperture 106.

The material that the elongated body 102 is constructed of may also havea natural porosity and permeability. For example, the elongated body ofthe cover plate may be constructed of a metal mesh or composite materialhaving organic porosity and permeability characteristics.

The longitudinal length of the elongated body 102 of the cover plateassembly 100 may also be varied to change the characteristics of thethreshing concave grate. While a preferred embodiment of the inventionincludes an elongated body 102 having a longitudinal length suitablydimensioned to substantially cover the entire lateral circumference of athreshing concave grate, other embodiments may include elongated bodieshaving lesser longitudinal lengths so as to cover only a portion of thelateral circumference of a threshing concave grate. For example, withreference to FIG. 5B, while a preferred embodiment of the cover plateassembly 100 of the present is dimensioned to substantially cover theentire lateral circumference of a threshing concave grate (i.e., fromaxial bar 148 a (A) to axial bar 148 a′ (B), other embodiments of thecover plate assembly of the present invention may include elongatedbodies having lesser longitudinal lengths so as to cover only a portionof the lateral circumference of a threshing concave grate (i.e., fromaxial bar 148 a (A) to axial bar 148 a″ (C)).

With reference now to FIGS. 8A-B another preferred embodiment of thecover plate assembly 100B of the present invention is shown. The coverplate assembly 100B features an elongated body having an adjustablewidth. The cover plate assembly 100B is dimensioned to fit within asection of a threshing concave grate 140 configured between two parallelarcuate rails (e.g., arcuate side rail 144 and middle support rail 151).The elongated body of the cover plate assembly 100B is comprised of twoelongated plates 102 a, 102 b, which are attached in a slidablyadjustable configuration for adjusting the lateral dimension or width ofthe cover plate assembly 100B. In a preferred embodiment, the twoelongated plates 102 a, 102 b are attached to each other by means of aplurality of bolts 108 attached to a first or main plate 102 a andcaptured in slots 109 formed in a second or accessory plate 102 b. Themain plate 102 a features panel sections 103 configured on each of theopposing ends which span the entire section width of the threshingconcave grate 140 while the width of the middle section 103 a of themain plate 102 a is less than the full section width of the of thethreshing concave grate 140. The second or accessory plate 102 b ispositioned in a slidable configuration with the first or main plate 102a so that the opening in the middle section 103 a of the main plate 102a may be adjusted as desired. As with previous embodiments, theelongated plates 102 a, 102 b of the cover plate assembly 100B mayinclude holes or apertures 116 to further adjust the flowcharacteristics of the adjustable cover plate assembly 100B.

The cover plate assembly 100B further includes a latching mechanism 115that maintains the lateral position of the cover plate assembly 100B sothat the clasp elements 104, 106 stay locked in position about theirrespective axial bars 148. For example, as depicted in FIG. 8A, thelatching mechanism 115 may comprise a turn-buckle tension deviceconfigured between an anchor bracket 110 attached to the exterior-facingside of the cover plate main body 102 a and an anchor device 132 securedto an end plate 149 of the concave grate 140. In an alternativeembodiment, the end latching mechanism 115 may comprise a conventionaltension draw latch assembly. Indeed, one skilled in the art willunderstand that a wide variety of latching mechanisms can be employed toapply a tension force between the anchor bracket 110 attached to theelongated body 102 and the anchor device 132 secured to an end plate 149or side rail 144 of the threshing concave grate 144.

As shown in FIG. 8B, the latching mechanism 115 may also comprise aturn-buckle tension device configured between an anchor device 132Asecured to a side rail 144 of the concave grate assembly 140 and ananchor bracket 110 attached to the exterior-facing side of the maincover plate body 102 a. As previously disclosed, the anchor device 132Bmay alternatively comprise a bar extending between the opposing siderails 144 of the concave grate assembly 140. The anchor bracket 110attached to the main cover plate body 102 a may be rigidly attached(e.g., welded) to the exterior-facing side of the main cover plate body102 a. Alternatively, the anchor bracket 110 may pivotally attached tothe exterior-facing side of the main cover plate body 102 a by means ofa pivoting rivet assembly 111. The pivoting rivet assembly 111 enablesthe anchor bracket 110 to be selectively angled and configured foreither an end mounted anchor device 132 or a side-rail mounted anchordevice 132B.

The cover plate assembly 100B may also or alternatively include one ormore side latching mechanisms 60 that maintain the lateral position ofthe main cover plate assembly 100B within the side rails 144 so that thehooking clasp elements 104, 106 stay engaged about their respectiveaxial bars 148. As mentioned previously, the side latching mechanisms 60may be used as an alternative to, or in addition to, the previouslydisclosed end latching devices (e.g., 110, 115, 132). For example, asshown in FIG. 8B in a preferred embodiment, the side latching mechanism60 may comprise at least one sliding bolt latch mechanism 62 attached tothe main cover plate 100 b and configured to engage a corresponding holedrilled in the side rail 144 of the concave grate assembly 140. Asdepicted, the sliding bolt latch mechanism may include a biasing element(e.g., spring or cam) to bias the sliding bolt in the locked or engagedposition. In another embodiment, the side latching mechanism 60 maycomprise at least one tension draw latch assembly 66 (see FIG. 4B)configured to engage a latch catch 67 attached to or formed into theside rail 144 of the concave grate assembly 140. Indeed, one skilled inthe art will understand that a wide variety of side latching mechanismscan be employed to secure the configuration of the main cover plate body102 b on the concave grate assembly 140.

The cover plate assembly of the present invention improves the threshingcapability of the rasp bar threshing cylinder while simultaneouslypermitting the capture of additional threshed grain. Moreover, themethods for using the cover plate assembly of the present inventionenables a single set of threshing concave grate assemblies to betterharvest a wider variety of crop types.

The cover plate assembly of the present invention eliminates the need tochange threshing concave grates when harvesting harder to thresh cropsand allows the operator to simply attach cover plate assemblies to thebackside (i.e., exterior) of the threshing concave grates. A pluralityof cover plate assemblies of the present invention can be readily addedto or removed from a combine harvester depending on how difficult thecrop is to thresh. In general, crop material that is more difficult tothresh requires more cover plate assemblies so that the crop material isheld in the threshing section longer. By adding cover plate assembliesof the present invention to a combine harvester, the operator can adjustthe rate at which the crop material moves through the threshingconcaves, facilitating more crop material rubbing on crop material, andthereby providing superior threshing capability with less grain damage.In addition, the strategically placed and engineered holes or apertures116 in the cover plate assembly allow for grain to be captured as it isthreshed and retained by the combine. Moreover, it prevents theseparation grate assemblies, whose purpose is to unload threshed grain,from becoming overloaded causing grain to be lost out the back of thecombine.

Methods employing the cover plate assembly of the present invention alsoenhance the harvesting effectiveness of combine harvesters whenharvesting high-moisture crops. For example, high-moisture corn kernelsare harder to separate from the cob, which necessitates the need for thecrop material to stay in the threshing section longer. The cover plateassembly can be used to adjust the flow rate of the threshing concave,keeping the crop material (i.e., corn in this particular instance) inthe threshing section for a longer time, thereby enabling the threshingsection to better separate grain from chaff.

Methods employing the cover plate assembly also enhance the harvestingeffectiveness of combine harvesters when harvesting delicate, dry, oreasy to crack and/or split crops. For example, edible beans are delicateand are known to crack and split easily. The addition of the cover plateassembly to a threshing concave grate creates a cushion of air whichprovides for a softer thresh by means of more crop material rubbing oncrop material. With the installation the cover plate assembly on thethreshing concave grates, the rotor speed can be decreased preventingneedless damage to the crop. The air cushion created by the cover plateassembly enables more material-on-material threshing. The clearance ordistance between the concave and rotor can also be increased whichreduces compressing the crop against the concave thereby decreasing themechanical damage to the crop. Furthermore, increasing theclearance/distance between the concave and rotor also increases thevolume of crop material that can be processed, thereby allowing theoperator to increase the ground speed of the agricultural thresher. Byincreasing the volume of crop material being processed, the rotor isfull of more crop material, consequently resulting in morematerial-on-material threshing and less grain damage (e.g., cracks andsplits).

Methods employing the cover plate assembly of the present invention alsoenhance the harvesting effectiveness of combine harvesters whenharvesting crops that have a lot of small leafy, foreign material aroundseed. Material such as this often ends up intermixed with the harvestedseed. Material other than grain (MOG), results in dockage/discount onprice per unit the farmer receives when selling the crop. For example,when harvesting sunflower seeds, the seeds thresh easily but there is alot of leafs, pedals and other foreign material surrounding the seeds.When sunflowers are harvested much of this MOG falls down through thethreshing concave grates and oftentimes ends up in the grain tank withthe sunflower seeds. The cover plate assembly of the present inventioncan be used as a course filter to reduce or close the large gaps in thethreshing concave grates filtering out a significant portion of the MOG.However, the apertures in the cover plate assemblies will allow thesmall sunflower seed to still fall through and end up in the tank.

The present invention addresses and overcomes the aforementionedlimitations of the prior art by providing a cover plate assembly thatrestricts the rate of speed at which the crop moves through thethreshing concave section, so that the crop is in the threshing concavesection which improves the separation of grain and chaff. This provesespecially beneficial for hard-to-thresh, delicate and high-moisturecrops and allows one set of concaves to be more versatile in all crops.From one crop to the next, cover plate assembly can easily and quicklybe added or removed depending on how difficult the crop is to thresh.The cushion of air that is created by the cover plate assembly allowsfor more material to be processed through a rotor, facilitating morematerial-on-material rubbing, and thereby producing a cleaner grainsample with less mechanical damage.

It will now be evident to those skilled in the art that there has beendescribed herein an improved method and apparatus for readily adjustingthe flow characteristics of the threshing concave grates on rasp barthreshing cylinder system. Although the invention hereof has beendescribed by way of a preferred embodiment, it will be evident thatother adaptations and modifications can be employed without departingfrom the spirit and scope thereof. The terms and expressions employedherein have been used as terms of description and not of limitation; andthus, there is no intent of excluding equivalents, but on the contraryit is intended to cover any and all equivalents that may be employedwithout departing from the spirit and scope of the invention.

I claim:
 1. A method for adjusting the flow characteristics of a concavegrate on a rasp bar threshing cylinder system, the method comprising:attaching a cover plate assembly to the exterior surface of the concavegrate, the cover plate assembly comprising an elongated body dimensionedto fit between two parallel arcuate side rails on the exterior of theconcave grate; said elongated body having two opposing ends, each endhaving a clasp element formed therein for grasping onto separate axialbars spanning the parallel arcuate rails and locking said body in asupinated position against the exterior of said concave grate; and alatching mechanism for maintaining the position of said elongated bodyrelative to said concave grate so that each of said clasp elementsmaintain its grasp on its respective axial bar, wherein said latchingmechanism comprises an anchor bracket attached to an exterior-facingside of said elongated body and selectively connected to an anchordevice secured to said concave grate.
 2. The cover plate assembly ofclaim 1, wherein said anchor device is attached to one of said siderails of the concave grate.
 3. The cover plate assembly of claim 1,wherein said anchor device is attached to an end plate of said concavegrate.
 4. The cover plate assembly of claim 1, wherein said anchordevice comprises a bar attached to and extending between said side railsof the concave grate assembly.
 5. A method for enhancing the harvestingeffectiveness of a combine harvester having a rasp bar threshingcylinder system, the method comprising: adjusting the flowcharacteristics of crop material through a threshing section byattaching a cover plate assembly to an exterior surface of a concavethreshing grate, the cover plate assembly comprising: an elongated bodydimensioned to fit between two parallel arcuate side rails on theexterior of the concave grate; said elongated body having two opposingends, each end having a clasp element formed therein for grasping ontoseparate axial bars spanning the parallel arcuate rails and locking saidbody in a supinated position against the exterior of said concave grate;and a latching mechanism for maintaining the position of said elongatedbody relative to said concave grate so that each of said clasp elementsmaintain its grasp on its respective axial bar, wherein said latchingmechanism comprises at least one side latching mechanism attached to anexterior-facing side of said elongated body for securing said elongatedbody to at least one of said side rails.
 6. The method of claim 5,wherein said adjusting step comprises slowing said crop material flowrate through the threshing section enabling the threshing section tobetter separate grain from chaff.
 7. The method of claim 5, wherein saidadjusting step further comprises decreasing rotor speed of the threshingcylinder system and using an air cushion created by the cover plateassembly to enable more material-on-material threshing.
 8. The method ofclaim 7, further comprising increasing the distance between a rotor ofthe threshing cylinder system and the concave grate to reducecompression of crop material.
 9. A method for enhancing the harvestingeffectiveness of a combine harvester, having a rasp bar threshingcylinder system, when harvesting crops having MOG around seed, themethod comprising: attaching a cover plate assembly to the exteriorsurface of a concave grate to act as a course filter to filter out asignificant portion of MOG during harvesting, the cover plate assemblycomprising: an elongated body dimensioned to fit between two parallelarcuate side rails on the exterior of the concave grate; said elongatedbody comprising a plurality of holes formed in said elongated body andhaving two opposing ends, each end having a clasp element formed thereinfor grasping onto separate axial bars spanning the parallel arcuaterails and locking said body in a supinated position against the exteriorof said concave grate; and a latching mechanism for maintaining theposition of said elongated body relative to said concave grate so thateach of said clasp elements maintain its grasp on its respective axialbar, wherein said latching mechanism comprises at least one sidelatching mechanism attached to an exterior-facing side of said elongatedbody for securing said elongated body to at least one of said siderails.
 10. The method of claim 9, wherein said latching mechanismcomprises a sliding bolt latch mechanism configured to engage acorresponding hole formed in one of said side rails of said concavegrate.
 11. The method of claim 9, wherein said latching mechanismcomprises a tension draw latch assembly attached to said exterior-facingside of said elongated body and configured to engage a latch catchconfigured on one of said side rails of said concave grate.
 12. Themethod of claim 9, further comprising adjusting the cover plate assemblyfilter capacity by plugging one or more of said plurality of holes. 13.The method of claim 9, wherein said adjusting step comprises pluggingone or more of said plurality of holes with a screw-in or pop-in plug.14. The method of claim 9, wherein said adjusting step comprisesplugging one or more of said plurality of holes with a flapper coverpositioned over one or more of said plurality of holes.
 15. The methodof claim 9, wherein said adjusting step comprises plugging one or moreof said plurality of holes with a movable panel positioned over one ormore of said plurality of holes.
 16. The method of claim 9, wherein thewidth of said elongated body is adjustable.
 17. The method of claim 16,wherein said elongated body comprises a main plate having a sectiondimensioned to be less than the distance between said two parallelarcuate rails and an accessory plate positioned in a slidableconfiguration with said main plate so as to adjust the width of saiddimensioned section of said main plate.
 18. The method of claim 17,further comprising configuring the accessory plate so as to maximize theopening of the section dimensioned to be less than the distance betweenthe two parallel arcuate rails.
 19. The method of claim 17, furthercomprising configuring the accessory plate so as to minimize the openingof the section dimensioned to be less than the distance between the twoparallel arcuate rails.
 20. The method of claim 17, further comprisingforming a plurality of holes in the main plate and accessory plate ofsaid elongated body.